Refrigerator



Feb.8, 1938. T. LjPoT'rER 2,107,753

. REFRIGERATOR l original Filed March 7, 193s 7 'f f l Il l 1 UIMM i.

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IlA l 1|, ,7 l IIIII'.. I rlllln l A' I M ATTORNEY Patented Feb. 8,1938;

UNITED :STATES REFBIGEBTOB Thomas '1. Potter, Buffalo, N. Y.

Applicants mmh 7, im, serial Renewed June 16, 1931 schim.

tofore, little. attention has been paid to atmos'- pheric conditioning of food storage compartments. In the ordinary household refrigerator a freezing unit is located in the food storage chamber. This unit consists of an expansion tank or f a coil for refrigerant in the form of a hollowchamber adapted to receive trays for freezing ice cubes and various forms of desserts. The freezing .unit must be 'maintained at a temperature far below the freezing point in order to effect rapid freezing ofthe water or desserts'placed therein. As a result of this arrangement, the air in the food chamber deposits its moisture by condensa- 20 tionon the walls of the freezing unit, and this moisture is immediately turned into ice. The

freezing unit thus rapidly dries out the air. Because of the dryness of the atmosphere many foods are wilted, shriveled, or otherwise damaged. To overcome this diiculty, it is commonly recommended that the foods be placed in closed containers, but aside from the bother of covering allr` foods and of iinding room for all the closed con- A tainers, there is another serious drawback, name- 1 30A ly, that moist food kept in the stagnant air within the container is apt to become moldy, even vat temperatures close to the freezing point.

In a copending applicationSerial No. 516,032,

led February 16, 1931, a refrigerator is described low temperature, say 40 degrees F., by an expansion coil of the non-frosting type, while the freezing unit of the refrigerator is placed in a separate chamber where a temperature far below 40 freezing is maintained. This arrangement provides a' chamber in which the atmosphere is very dry and coldand another chamber in which the atmosphere is cool enough to preserve food but in which a considerable content of moisture may be maintained.

It is well-knownthat the amount of water vapor that the air holddepends upon its temperture and 100 per c'ent. humidity at one humidity at another.

content will deposit its moisture in the form of dew or frost when it is chilled below the temperature at which ,such vapor contentcan be sup ported. At '40 degrees F. air willbe at the satin which the food cooling chamber is kept at a'V temperature is very different from 100 per cent.-

Air with a -certain vapor 1 ura'tion point when it contain` 36.4 grains of vapor.

per pound of dry air. 'At 12 degrees F. it cannot hold more than 10.13 grains of vapor and at 0 degrees F. not more than 5.47 grains. Hence the greater the dierence in temperature between the freezing unit and the average air temperature in the food chamber, the more actively will said unit pump moisture out of the air-and if such moisture is immediately frozen there will be no way for the `air to pickit up again. By using a non-frostingunit insteadof the customary low freezing unit, there is but a slight drop in temperature of the' air that contacts with said non-frosting unit and abstrationv of moisture from the air will proceed very slowly, stopping when the average moisture in the air is slightly reduced. If, for instance, the average temperature in the chamber is 40 degrees F. and the air is at its saturation point, that isper cent. huxnidity, and if the air contacting with the coil is chilled to say 38 degrees F., there will be a deposit of moisture on the coil, which, however, will stop when the vapor content is reduced to 33.66 grains per pound, or, in other words, when the humidity has been reduced to 924 per cent. Theoretically this slight dryness o f the atmosphere will cause a certain amount of vapor absorption from moist foods, but the extent of such absorption will be almost negligible and certainly in no sense comparable to that prevailing in the ordinary refrigerator.

An object of the present invention is to supply moisture to the cooling chamber of a refrigerator so as to maintain a high percentage of humidity. Another object is to provide means for restoring to the air in the chamber the moisture abstracted therefrom by the cooling unit, so that the vapor in the air will be maintainedclose to its saturation point. Where a freezing unit isA used this cannot be done because the vapor deposited thereon-is solidifled and hence substantially eliminated from reentry into the air. .'However, with a. non-frosting unit the vapor is deposited as dew and my in-v ventionv contemplates trapping this dew in aA humidifier from which the vapor may be picked up again by the surrounding air.

Other objects and advantages of my invention .will appear inthe `following description of a preferred embodiment, and thereafter the novelty and scope of the invention will be pointed out in the claims. 1

In theaccompanying drawing; f

Figure 1 is a fragmental view invertical section of a refrigerator embodying myinvention, said section being taken substantially on the'I line ll of Fig."2; and

A unit as is commonly required in ordinary prac-- the cabinet.

Fig. 2 is a fragmental view in vertical section taken substantially on the line 2-2 of Fig. 1.

In the drawing, I have used the reference numeral I to indicate a refrigerator cabinet. This cabinet has an upper food storage chamber I I and a lower food storage chamber I2 with a wall I2 therebetween which thermally insulates one chamber from the other. In the lower chamber I2 is placed'a freezing unit I4 formed of a plate `or shelf on which trays may be placed for forming ice cubes or for freezing desserts. It is intended that this freezing unit be maintained at a very low temperature, so as to effect rapid freezing of the foods placed thereon or in the space below the shelf. I have found that if the freezing unit be maintained at a temperature close to or below zero Fahrenheit any moisture that is abstracted from the surrounding atmosphere will collect thereon as a snow-like frost which may be readily brushed or scraped off, while if the temperature of the freezing unit is higher the moisture will collect as ice and will gradually build insulation around the freezing unit. Thus, by maintaining a low temperature in the freezing unit Il, it will not be necessary to de-f'rost this tice.

In the upper chamber I I, I provide a non-frosting unit I5' which is connected in series with the unit' I4 in a refrigerating line I6, the latter being embedded in the insulation I'I in the rear wall of a coil I8 through which the refrigerant flows and is fitted with transverse plates or vanes I9 which are adapted to pick up the heat from the chamber II, such heat being carried into the coil at such'a rate that they are not cooled below the freezing point. In fact the average temperature of these plates is only slightly below that of the air circulating past them.

A vertical partition 20 is provided to conceal the non-frosting unit. This partition is spaced from the unit and also from the top of the chamber so that air may circulate over the partition and on being chilled by contact with the non-frosting unit will move by gravity downward into the lower part of the chamber.

Placed directly under the unit I5is avhumidil er 2I. 'I'his comprises a shallow pan 22 resting on a shelf 23. Supported in and projecting downwardly from the pan are two triangular end frames 24 which are connected at their corners by three rods 25. Ov`er these rods is stretched a sleeve 26 of fabric which serves as a wick.

In practice, the pan is partially filled with A water and the water is picked up by capillary action by the wick or sleeve 26. If the vapor content of the air is below the saturation point, moisture will be picked up from the wick to satisfy the deficiency. This conditions the air in- The non-frostingv unit comprises flows over the wick. In this way, I have provided means for maintaining a balanced humidity in the upper chamber of the refrigerator, while in the lower chamber may be placed foods which will not be harmed by desi'ccation.

Having thus described a preferred embodiment of my invention what I claim as new and desire to secure by Letters Patent is as follows:

1. A refrigerator formed with a food chamber,

a non-frosting coil therein, means for circulating a refrigerant through the coil, said coil serving to maintain the'air in the chamber at a low but non-freezing temperature, a pan under the coilv in position to catch any drip of moisture condensed from said air upon the coil, and a broad wick dipping into and extending outwardly from the pan to facilitate reabsorption of the moisture by the air.

'2. A refrigerator formed with a food chamber,

a non-frosting coil therein, means for circulating a refrigerant through the coil, a partition adapted to guide a current of air downward past the coil,

a pan under the coil, a frame of triangular crosssection in the pan, and a wick in the form of a sleeve ttedover the frame with one face of the wick seated on the pan and another face projecting'from the pan 'in a plane inclined to the direction of said current.

3. A refrigerator formed with a food chamber, a non-frosting coil therein and near the rear wall of the chamber, means for circulating a refrigerant through the coil, a. partitionv in front of the coil and adapted to direct a current of air downward past the coil, a pan under the coil, a frame having in cross-section the form of a right-angled triangle, a wick in the form of a sleeve fitted over the frame, one face of the sleeve being seated in the pan with a second face rising vertically from the pan axhacent said rear wall and the third face thereof inclined downwardly and forwardly toward the partition.

4. A humidier for a refrigerator comprising av pan, a wick forming an evaporating surface inclined with respect to the plane of the pan and 'with one edge of the wick dipping into the pan,

and a frame supporting the wick. l

5. A humidifier for a refrigerator comprising a pan, a frame of triangular cross-section, a wick in the form of a sleeve fitted upon the frame and adaptui to rest with one face thereof in thepan and theother two faces thereof projecting outwardly from the pan. 

